Acetabular liner extraction device, kit and associated method

Abstract

An extraction device for removing a liner from an acetabular cup is provided. The extraction device includes a jaw and a handle. The jaw is for cooperation with the liner and including a portion of the jaw for penetrating into the liner. The handle is operably associated with the jaw and is adapted for gripping the extraction device.

1. An extraction device for removing a liner from an acetabular cup, said extraction device comprising:
 a jaw for cooperation with the liner, said jaw being sized and shaped to fit inside the liner and including at least two movable jaw segments, each of at least two jaw segments including at least one pointed tooth for penetrating into an inner periphery of the liner; 
 a handle operably associated with said jaw, said handle having a longitudinal axis, said handle adapted to allow a user to grip the extraction device; 
 a frame for supporting the handle, at least a portion of the frame cooperating with an acetabular cup; and 
 an actuator operably associated with said jaw and with said handle, actuator having a tapered component that is coupled to the handle such that when the handle is moved along its longitudinal axis the tapered component also moves along the longitudinal axis, said tapered component engaging said at least two moveable jaw segments such that as said handle and said tapered component move along the longitudinal axis, the moveable jaw segments are moved relative to one another; 
 wherein said handle defines an aperture therethrough, the aperture defining a longitudinal axis thereof; and 
 wherein said actuator comprises a portion thereof moveably positioned in the aperture. 
 
   
   
     2. The extraction device of  claim 1 , wherein said jaw comprises a plurality of spaced apart jaw components. 
   
   
     3. The extraction device of  claim 1 , wherein the pointed tooth of said jaw for penetrating into the liner comprises a tapered protrusion. 
   
   
     4. The extraction device of  claim 3 , wherein the tapered protrusion comprise a tip having a length of less than 0.01 millimeters. 
   
   
     5. The extraction device of  claim 3 , wherein the tapered protrusion has a height of from about 1 millimeter to 5 millimeters. 
   
   
     6. The extraction device of  claim 1 , wherein said jaw and said handle cooperate to provide a first position for said jaw spaced from the liner and a second position for said jaw in contact with the liner. 
   
   
     7. The extraction device of  claim 1 , wherein said jaw and said actuator comprise a cam connection there between to provide motion between said jaw and said handle. 
   
   
     8. The extraction device of  claim 1 , wherein said jaw and said actuator comprise a tapered connection there between to provide motion between said jaw and said handle. 
   
   
     9. The extraction device of  claim 1 , wherein said jaw and said actuator comprise a threaded connection there between to provide motion between said jaw and said handle. 
   
   
     10. The extraction device of  claim 1 , wherein said jaw is generally cylindrical. 
   
   
     11. The extraction device of  claim 1 , wherein said jaw has a shape that is generally a truncated sphere, truncated on both opposed poles of the sphere and defining an arcuate periphery therebetween. 
   
   
     12. The extraction device of  claim 11 :
 wherein a portion of said jaw is adapted for penetrating into the liner; and 
 wherein said portion is positioned on the arcuate periphery of the jaw. 
 
   
   
     13. The extraction device of  claim 12 , wherein said portion is made of a metal. 
   
   
     14. The extraction device of  claim 1 , wherein at least one of said handle and said jaw are adapted to provide sufficient penetration of the jaw into the liner to permit a snap ring to be buckled out of a groove in the acetabular cup and removed simultaneously with the liner. 
   
   
     15. A kit for use in revision hip surgery, comprising:
 an extraction device for removing a liner from an acetabular cup, said extraction device including a jaw for cooperation with an inside periphery of the liner, said jaw including at least two movable jaw segments, each of at least two jaw segments including at least one pointed tooth for penetrating into the liner, a handle operably associated with said jaw, said handle adapted for allowing a user to grip the extraction device, a frame for supporting the handle, at least a portion of the frame cooperating with an acetabular cup, and an actuator operably associated with said jaw and with said handle, said actuator having a tapered component that is coupled to the handle such that when the handle is moved along its longitudinal axis the tapered component also moves along the longitudinal axis, said tapered component engaging said at least two moveable jaw segments such that as said handle and said tapered component move along the longitudinal axis, the moveable jaw segments are moved relative to one another; 
 a polymer revision cup; and 
 a snap ring. 
 
   
   
     16. The kit of  claim 15 , wherein said jaw and said handle cooperate to provide a first position for said jaw spaced from the liner and a second position for said jaw in contact with the liner. 
   
   
     17. A method for performing orthopaedic revision surgery, the method includes the steps of:
 inspecting an implanted acetabular cup assembly including a shell, a polymer liner and a snap ring in vivo in a patient; 
 determining if the polymer liner should be replaced from the shell of the acetabular cup assembly; 
 using an extraction device for removing the liner from the shell, said extraction device including a jaw having at least two movable jaw segments, each of at least two jaw segments including at least one pointed tooth for cooperation with an inner periphery of the liner, and a frame for supporting the handle, at least a portion of the frame cooperating with the shell; 
 activating an actuator on the extraction device to provide relative motion between said two jaw segments; 
 grasping the inside of the liner with the at least two jaw segments; and 
 extracting the liner and the snap ring from the shell simultaneously with the extraction device while the shell is still implanted in the patient.